Method of manufacturing an activated composite web and an activated composite web for absorptive devices

ABSTRACT

A method of manufacturing an activated composite web includes laminating a film layer to a nonwoven web to form a composite web, forming a plurality of apertured protuberances in the film layer, and passing the composite web through intermeshing elements to form an activated composite web. The intermeshing elements form a plurality of first lanes, with first widths, substantially unaffected by activation, and a plurality of second lanes, with second widths. The second widths are less than the first widths. Portions of the plurality of apertured protuberances define first apertures in the first lanes and second apertures in the second lanes. The cross-sections of the second apertures are larger than the first apertures. The first apertures have their major axes substantially aligned in the first direction while the second apertures have their major axis substantially aligned in the second direction. An activated composite web also is provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/918,803, filed on Mar. 12, 2018, which claims the benefit of priorityfrom U.S. Provisional Patent Application Ser. No. 62/470,671, filed Mar.13, 2017, the entire contents of both of which are incorporated hereinby reference.

FIELD

The present invention is related to an activated composite web that maybe used in an absorptive device, and methods for making the activatedcomposite web.

BACKGROUND

Plastic formed films and nonwovens are used as topsheets in absorptivedevices such as feminine hygiene products, adult incontinence products,and baby diapers, for example. A topsheet is a top layer of theabsorptive device that contacts the skin of the user (wearer) of theabsorptive device. Nonwoven materials are often used as topsheetcomponents of such absorptive devices where it is desirable to achievesoftness due to the contact of the topsheet with the skin of the wearerof the absorptive device. Although a ratio of high loft to totalthickness of the nonwoven material is often perceived to be soft andcool when used against the skin, special processing is typically neededto achieve such characteristics, which may increase the cost of theproduct.

For topsheets that are made from a formed film, it is desirable to havethe visual appearance and softness of a soft cloth, instead of a stiffplastic film. Although topsheets that are made from plastic filmstypically have better performance characteristics when used in theabsorptive device as compared to topsheets that are made from nonwovenmaterials, a topsheet made from a plastic film may have a visualappearance that is higher in gloss and therefore may be more“plastic-looking” than a nonwoven topsheet. Additionally, a plastic filmtopsheet may feel more “sticky” or “tacky” to the wearer than a nonwoventopsheet.

It is desirable to have a lightweight web that may be used in anabsorptive device as, for example, a topsheet that has the performanceattributes associated with a formed film and softness attributesassociated with a nonwoven material.

SUMMARY

According to one non-limiting embodiment, the present invention providesa method of manufacturing an activated composite web. The methodincludes laminating a film layer to a nonwoven web to form a compositeweb, forming a plurality of apertured protuberances in the film layerwith a pin punching unit, and passing the composite web throughintermeshing elements to form an activated composite web. Theintermeshing elements are constructed and arranged to form a pluralityof first lanes substantially unaffected by activation aligned in a firstdirection and having a first width in a second direction substantiallyperpendicular to the first direction and also to form a plurality ofsecond lanes aligned in the first direction and having a second widthless than the first width in the second direction in the activatedcomposite web. A first portion of the plurality of aperturedprotuberances forms a plurality of first apertured protuberances havinga plurality of corresponding first apertures with first cross-sectionalareas. The first apertured protuberances are located in the first lanes.A second portion of the plurality of apertured protuberances forms aplurality of second apertured protuberances having a plurality ofcorresponding second apertures with second cross-sectional areas, eachof the second cross-sectional areas being larger than each of the firstcross-sectional areas. The second apertured protuberances are located inthe second lanes. Each of the first apertures has a first major axissubstantially aligned in the first direction. Each of the secondapertures has a second major axis substantially aligned in the seconddirection.

In another embodiment of the method, the film layer has a basis weightof between about 6 gsm and about 20 gsm.

Still further, it is contemplated that the method may be provided suchthat the nonwoven web has a basis weight of between about 8 gsm andabout 18 gsm.

The method also may provide so that the plurality of aperturedprotuberances are arranged in a pattern having a mesh count of at least35.

In another non-limiting embodiment, the present invention provides anactivated composite web, that includes a composite web having a nonwovenlayer and a film layer attached to the nonwoven layer. The film layerincludes a plurality of apertured protuberances. The composite web isactivated by stretching with intermeshing elements to form the activatedcomposite web. The activated composite web has a plurality of firstlanes substantially unaffected by activation aligned in a firstdirection and a first width in a second direction substantiallyperpendicular to the first direction. A first portion of the pluralityof apertured protuberances forms a plurality of first aperturedprotuberances having a plurality of corresponding first apertures withfirst cross-sectional areas, the first apertured protuberances locatedin the first lanes. The activated composite web also has a plurality ofsecond lanes aligned in the first direction and a second width less thanthe first width in the second direction. The first lanes and the secondlanes alternate with each other in the second direction. A secondportion of the plurality of apertured protuberances forms a plurality ofsecond apertured protuberances having a plurality of correspondingsecond apertures with second cross-sectional areas, each of the secondcross-sectional areas being larger than each of the firstcross-sectional areas. The second apertured protuberances are located inthe second lanes. Each of the first apertures has a first major axissubstantially aligned in the first direction. Each of the secondapertures has a second major axis substantially aligned in the seconddirection.

In one further contemplated embodiment of the activated composite webaccording to the present invention, the film layer has a basis weight ofbetween about 6 gsm and about 20 gsm.

It is contemplated that the activated composite web may be constructedwhere the nonwoven web has a basis weight of between about 8 gsm andabout 18 gsm.

Still further, in the activated composite web according to the presentinvention, the plurality of apertured protuberances are arranged in apattern having a mesh count of at least 35.

These and other aspects, features, and characteristics of the presentinvention, as well as the methods of operation and functions of therelated elements of structure and the combination of parts and economiesof manufacture, will become more apparent upon consideration of thefollowing description and the appended claims with reference to theaccompanying drawings, all of which form a part of this specification.It is to be expressly understood, however, that the drawings are for thepurpose of illustration and description only and are not intended as adefinition of the limits of the invention. As used in the specificationand in the claims, the singular form of “a”, “an”, and “the” includeplural referents unless the context clearly dictates otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

The components of the following figures are illustrated to emphasize thegeneral principles of the present disclosure and are not necessarilydrawn to scale. Reference characters designating correspondingcomponents are repeated as necessary throughout the figures for the sakeof consistency and clarity.

FIG. 1 is a schematic representation of an apparatus for manufacturingan activated, lightweight, composite web according to embodiments of theinvention;

FIG. 2 is a schematic representation of a portion of the apparatusillustrated in FIG. 1 according to embodiments of the invention;

FIG. 3 is a schematic representation of a cross-section of a portion ofan activated, lightweight, composite web according to embodiments of theinvention;

FIG. 4 is a photograph of one side of the activated, lightweight,composite web according to embodiments of the invention;

FIG. 5 is a photograph of one side of the activated, lightweight,composite web, opposite the side illustrated in FIG. 4, according toembodiments of the invention;

FIG. 6 is a photograph of a zoomed-in portion of the side of theactivated, lightweight, composite web illustrated in FIG. 5;

FIG. 7 is a schematic representation of the side of the activated,lightweight, composite web illustrated in FIG. 5;

FIG. 8 is a photograph of a cross-section of the activated, lightweight,composite web of FIG. 5; and

FIG. 9 is a photograph of a zoomed-in portion of the cross-section ofthe activated, lightweight, composite web of FIG. 8.

DETAILED DESCRIPTION

Throughout this description, the term “web” refers to a material capableof being wound into a roll. Webs can be film webs, nonwoven webs,laminate webs, apertured laminate webs, etc. The face of a web refers toone of its two dimensional surfaces, as opposed to its edge. The term“composite web” refers to a web that comprises two or more separate websthat are attached to each other in a face to face relationship. Theattachment can be through the edges of the component webs, although thecomponent webs lie in a face to face relationship with each other, orthe attachment can be at particular locations across the component webs.

The term “film” in this description refers to a web made by extruding amolten sheet of thermoplastic polymeric material by a cast or blownextrusion process and then cooling said sheet to form a solid polymericweb. Films can be monolayer films, coextruded films, coated films, andcomposite films. Coated films are films comprising a monolayer orcoextruded film that are subsequently coated (for example, extrusioncoated, impression coated, printed, or the like) with a thin layer ofthe same or different material to which it is bonded. Composite filmsare films comprising more than one film where the at least two films arecombined in a bonding process. Bonding processes may incorporateadhesive layers between the film layers.

Throughout this description, the expression “apertured films” denotesfilms in which there exist a plurality of holes that extend from onesurface to a second surface. A two dimensional apertured film is a filmin which no three dimensional structure exists in the holes, which thenconnect the second surface of a flat film to the first surface of thefilm. A “formed film” is a three dimensional film with protuberances,and a three dimensional apertured film is a film in which a threedimensional structure exists in the apertures (e.g., the apertures havea depth that is thicker than the thickness of the film) or theprotuberances have apertures therethrough.

The term “nonwoven” means a web comprising a plurality of fibers. Thefibers may be bonded to each other or may be unbonded. The fibers may bestaple fibers or continuous fibers. The fibers may comprise a singlematerial or may comprise a multitude of materials, either as acombination of different fibers or as a combination of similar fiberseach comprised of different materials. As used herein, “nonwoven web” isused in its generic sense to define a generally planar structure that isrelatively flat, flexible and porous, and includes staple fibers orcontinuous filaments. The nonwoven web may be the product of any processfor forming the same, such as nonwoven spunbond and melt blown nonwovenwebs. The nonwoven web may include a composite or combination of webs.In an embodiment, the nonwoven web is a spunbond material, made ofpolypropylene fiber. The nonwoven web may, however, comprise anypolymeric material from which a fiber can be produced and/or maycomprise cotton or other natural fibers. For example, the nonwoven webmay comprise fibers of polyethylene, polypropylene, elastomers,polyesters, rayon, cellulose, nylon, cotton (or other natural fibers),and blends of such fibers. Fibers that comprise different polymers mayalso be blended.

The term “extensibility” as used herein refers to the maximum amount ofstrain (in %, relative to the zero strain state) that can be applied toa web in a given direction by a tensile force without breakage offibers, or bonds between fibers. For a nonwoven web to be extensible inany given direction means that when a tensile force is applied to theweb in that direction, the web expands in that direction, and a strainis induced in the web, substantially without breakage of fibers, or ofbonds between fibers.

The term “screen” as used herein refers to a three-dimensional moldingapparatus comprising indentations and/or apertures and/or protrusionsused to form protuberances or apertures in films. In an embodiment,screens comprise tubular members, having a width and a diameter. Inalternative embodiments, screens comprise belts having a width and alength. The transverse direction is the direction parallel to the widthof the screen. The machine direction is the direction parallel to thedirection of rotation of the screen, and is perpendicular to thetransverse direction.

The term “protuberance” as used herein refers to a three-dimensionalmember comprising an apertured base portion located in the plane of thefirst surface of the film and a sidewall portion extending generally inthe direction of the second surface of the film. Each base portion has asidewall portion. Sidewall portions terminate in “ends” located in theplane of the second surface of the film. The ends of the protuberancesmay be apertured or unapertured. “Apertured protuberance” as used hereinrefers to a protuberance that has an aperture at its end in the plane ofthe second surface. The apertures in the base portions of theprotuberances, also called “primary apertures,” may be in the shape ofpolygons, for example squares, hexagons, pentagons, ellipses, circles,ovals, or slots, in a regulated or random pattern. In an embodiment, theapertures may be in the shape of a boat, as described in, for example,U.S. Pat. No. 7,198,836, which is incorporated herein by reference. Theprotubered ends, if apertured, are called “secondary apertures,” and maybe in the shape of polygons, e.g., squares, hexagons, pentagons,ellipses, circles, ovals, slots, or boats.

As used herein, the expression “absorbent articles” and “absorptivedevices” denote articles that absorb and contain body fluids and otherbody exudates. More specifically, an absorbent article/absorptive deviceincludes garments that are placed against or in proximity to the body ofa wearer to absorb and contain the various exudates discharged from abody.

As used herein, the term “activating” or “activation” refers to aprocess of stretching a material beyond a point where its physicalproperties are changed. In the case of a nonwoven web, sufficientactivation of the web will result in the nonwoven web being moreextensible and/or improving its tactile properties. In an activationprocess, forces are applied to a material causing the material tostretch. Formed film and nonwoven webs may be mechanically activated,for example. Mechanical activation processes comprise the use of amachine or apparatus to apply forces to the web to cause stretching ofthe web. Methods and apparatus used for activating webs of materialsinclude, but are not limited to, activating the web through intermeshinggears or plates, activating the web through incremental stretching,activating the web by ring rolling, activating the web by tenter framestretching, canted wheel stretchers or bow rollers, and activating theweb in the machine direction between nips or roll stacks operating atdifferent speeds to mechanically stretch the components, andcombinations thereof.

Referring now to FIG. 1, FIG. 1 illustrates an apparatus 100 that may beused to manufacture an activated, lightweight, composite web accordingto embodiments of the present invention. As illustrated, the apparatus100 includes an extrusion die 102 constructed and arranged to extrude apolymer melt curtain (molten polymer web) 104 onto vacuum formingcylinder 106. In an embodiment, the molten polymer web 104 may include apolyolefin selected from the group consisting of polyethylene,polypropylene, ethylene-vinyl acetate, and a metallocene-basedpolyolefin. The polyethylene may be selected from the group consistingof ultra low density polyethylene, linear low density polyethylene, andlinear medium density polyethylene. In an embodiment, the molten polymerweb 104 may include an elastomeric polymer selected from the groupconsisting of polypropylene based elastomers, ethylene based elastomers,copolyester based elastomers, olefin block copolymers, and styrenicblock copolymers.

The vacuum forming cylinder 106 includes a forming screen 108 and avacuum slot 110. A supply roll 112 of a nonwoven web 114 is provided ona spindle in a position that allows the nonwoven web 114 to be fed ontoa laminating roller 116 located adjacent to the vacuum forming cylinder106. As the nonwoven web 114 rotates around the laminating roller 116and into a nip 118 between the laminating roller 116 and the vacuumforming cylinder 106, the nonwoven web 114 contacts the polymer meltcurtain 104 while the polymer is still molten at an impingement pointbetween the forming screen 108 of the vacuum forming cylinder 106 andthe laminating roller 116. Desirably, the impingement point is directlyover the leading edge of the vacuum seal at the vacuum slot 110 of thevacuum forming cylinder 106.

The pattern of apertures in the forming screen 108 determines thepattern of protuberances in the formed film. In an embodiment of theinvention, the formed film layer includes a pattern of aperturedprotuberances having a mesh count of 57 (i.e. 57 apertures per linearinch), with each apertured protuberance having a cross-section in theshape of a boat (i.e. a boat shaped cell or “BSC”). Such a pattern maybe referred to as “57 BSC.” The boat shaped cell-type aperture isdescribed in further detail in U.S. Pat. No. 6,989,187, which isincorporated herein by reference. Other formed film aperture patternsthat are well known in the formed film art may also be useful, such ashexagon, square, or round apertures having mesh counts of, for example,100, 80, 60 or 40 apertures per linear inch. Patterns with a mesh countof 30 or less may lose the sensation of softness and may not respondwell to activation, which is described in further detail below.

In an embodiment, the formed film layer has a plurality of aperturedprotuberances having a mesh count of at least 35. In an embodiment, theapertured protuberances have a mesh count of at least 40. In anembodiment, the apertured protuberances have a mesh count of at least45. In an embodiment, the apertured protuberances have a mesh count ofat least 50. In an embodiment, the apertured protuberances have a meshcount of at least 55. In an embodiment, the apertured protuberances havea mesh count of at least 60. In an embodiment, the aperturedprotuberances have a mesh count of at least 65. In an embodiment, theapertured protuberances have a mesh count of at least 70. In anembodiment, the apertured protuberances have a mesh count of at least75. In an embodiment, the apertured protuberances have a mesh count ofat least 80. In an embodiment, the apertured protuberances have a meshcount of at least 85. In an embodiment the apertured protuberances havea mesh count of at least 90. In an embodiment, the aperturedprotuberances have a mesh count of at least 95. In an embodiment, theapertured protuberances have a mesh count of at least 100.

The fibrous web material of the nonwoven web 114 embeds partially intothe molten polymer web 104 to create a formed laminate web 120. The twowebs 104, 114 continue on over the vacuum slot 110 as aperturedprotuberances, described in further detail below, are formed in themolten polymer web 104. Air flow is initiated through the apertures inthe forming screen 108, which cools and solidifies the molten polymerweb 104 and, by becoming solid, the polymer web traps embedded fibersfrom the nonwoven web 114, thereby bonding the nonwoven web 114 to whatis now a formed film layer to form the vacuum formed laminate web 120.

The formed film layer may have a basis weight of between about 6 gsm andabout 20 gsm. In an embodiment, the formed film layer has a basis weightof about 6 gsm. In an embodiment, the formed film layer has a basisweight of about 7 gsm. In an embodiment, the formed film layer has abasis weight of about 8 gsm. In an embodiment, the formed film layer hasa basis weight of about 9 gsm. In an embodiment, the formed film layerhas a basis weight of about 10 gsm. In an embodiment, the formed filmlayer has a basis weight of about 11 gsm. In an embodiment, the formedfilm layer has a basis weight of about 12 gsm. In an embodiment, theformed film layer has a basis weight of about 13 gsm. In an embodiment,the formed film layer has a basis weight of about 14 gsm. In anembodiment, the formed film layer has a basis weight of about 15 gsm. Inan embodiment, the formed film layer has a basis weight of about 16 gsm.In an embodiment, the formed film layer has a basis weight of about 17gsm. In an embodiment, the formed film layer has a basis weight of about18 gsm. In an embodiment, the formed film layer has a basis weight ofabout 19 gsm. In an embodiment, the formed film layer has a basis weightof about 20 gsm.

The nonwoven web may have a basis weight of between about 8 gsm andabout 18 gsm. In an embodiment, the nonwoven web has a basis weight ofabout 8 gsm. In an embodiment, the nonwoven web has a basis weight ofabout 9 gsm. In an embodiment, the nonwoven web has a basis weight ofabout 10 gsm. In an embodiment, the nonwoven web has a basis weight ofabout 11 gsm. In an embodiment, the nonwoven web has a basis weight ofabout 12 gsm. In an embodiment, the nonwoven web has a basis weight ofabout 13 gsm. In an embodiment, the nonwoven web has a basis weight ofabout 14 gsm. In an embodiment, the nonwoven web has a basis weight ofabout 15 gsm. In an embodiment, the nonwoven web has a basis weight ofabout 16 gsm. In an embodiment, the nonwoven web has a basis weight ofabout 17 gsm. In an embodiment, the nonwoven web has a basis weight ofabout 18 gsm.

Returning to FIG. 1, the vacuum formed laminate web 120 is pulled off ofthe vacuum forming cylinder 106 by a peel roll 122 and proceeds totravel in a machine direction over an idle roll 124 and is introducedinto an activation nip 126. The activation nip 126 is formed when afirst intermeshing gear roller 128 is engaged with a second intermeshinggear roller 130 at a depth of engagement. The activation may be carriedout in the machine direction (MD) or in the transverse direction (TD)relative to the direction of motion of the activated, lightweight,composite web 132.

FIG. 2 illustrates an embodiment of the intermeshing gear (“IMG”)rollers 128, 130 that may be used in the apparatus 100 of FIG. 1 for TDactivation. As illustrated, the rollers 128, 130 are carried onrespective rotatable shafts 228 and 230, having their axes of rotationdisposed in parallel relationship. Each of rollers 128, 130 includes aplurality of axially-spaced, side-by-side, circumferentially-extending,equally-configured gears 232 that can be in the form of thin fins ofsubstantially rectangular cross section.

The spaces between adjacent gears 232 define recessed,circumferentially-extending, equally configured grooves 234. Withoutlimiting the present invention, the gears 232 also are referred to as“teeth 232” herein. The grooves 234 can be of substantially rectangularcross section when the gears 232 are of substantially rectangular crosssection. Thus, each of forming rolls 128, 130 includes a plurality ofspaced gears 232 and alternating grooves 234 between each pair ofadjacent gears 232. The gears 232 and the grooves 234 need not each beof the same width, however, and preferably, the grooves 234 have alarger width than that of the gears 232, to permit the material thatpasses between the forming rolls 128, 130 to be received within therespective grooves 234 and to be locally stretched. The vacuum formedlaminate web 120 uniquely responds to this stress, which results in theforming of an activated, lightweight, composite web 132 according to thepresent invention.

In MD activation, a view of the cross section of the forming rolls 128,130 looking down the axes of the rotatable shafts 228, 230 of theforming rolls 128, 130 would show gear teeth (not shown) cut into andaround the circumference of the forming rolls 128, 130, with their longaxes substantially parallel with the axes of the forming rolls 128, 130.The teeth on one forming roll 128 meshes into the grooves on theadjacent roll 130 in order to provide a stretching action to the web120.

The depth of engagement of the roller teeth, gears, or fins 232determines the degree of elongation to which the vacuum formed laminateweb 120 is subjected. A balance usually is drawn between the depth ofengagement of the roller teeth 232 and the composition of the vacuumformed laminate web 120, as these affect many important physicalproperties of the activated, lightweight, composite web 132. Some of thefactors affecting the choice of pitch, teeth depth, and depth ofengagement include the composition of the activated, lightweight,composite web 132, desired final properties (breathability, absorbency,strength, cloth-feel), and the width and diameter of the IMG rollers128, 130. The final application of the activated, lightweight, compositeweb 132 also affects these choices because it determines desired finalproperties. The width of the IMG rollers 128, 130 may present economicand technical limitations. In particular, as the width increases, theweight of the IMG rollers 128, 130 also increases, as does the amount ofdeflection experienced by the IMG rollers 128, 130. Deflection createsvariation not only in the process of stretching, but also in the processof making the IMG rollers 128, 130, particularly as the pitch and toothdepth increases. Those skilled in the art are capable of varying theparameters of the IMG rollers 128, 130 to achieve the desiredstretching, using the guidelines provided herein.

Returning to FIG. 1, the vacuum formed laminate web 120 is activated inthe activation nip 126 by the IMG rollers 128, 130 to form theactivated, lightweight, composite web 132, which may be introduced tofurther downstream steps such as adding treatment, slitting and windingof rolls, and the like, as desired for the end product.

FIG. 3 illustrates a schematic cross-section of a portion of alightweight composite web 300 in accordance with embodiments of theinvention. As illustrated, the lightweight composite web 300 includes aformed film layer 310 and a nonwoven layer 320. The cross-sectionillustrated is taken from a wide lane portion, which is described infurther detail below, of the lightweight composite web 300. The formedfilm layer 310 includes a plurality of apertured protuberances 312 thatextend away from the nonwoven layer 320. In an embodiment, the formedfilm layer 310 may be oriented so that the apertured protuberances 312extend towards the nonwoven layer 320. The orientation of the aperturedprotuberances 312 may be left to the discretion of the absorptive devicedesigner. Each apertured protuberance 312 includes an aperture 314 thatis surrounded by sidewalls 316 crowning at lands 318 that extend inbetween the apertures 314 of adjacent protuberances 312. The lands 318may be planar or slightly curved and the size of the lands 318 may rangefrom a measurable distance between apertures 314 to being very sharp andrazor-like with negligible distance.

The formed film layer 310 is attached to the nonwoven layer 320 at aplurality of fusion bond points 330 generally located at the lands 318of the formed film layer 310 so that the composite web 300 is laminatedwith sufficient peel force for keeping the layers 310, 320 attachedduring later conversion methods and ultimately during use where appliedstresses might tend to cause layer separation. A vacuum forminglamination method for causing this fusion bond 330 is described infurther detail in U.S. Pat. No. 6,242,074, which is incorporated hereinby reference.

In an embodiment, additional apertures may be formed through thecomposite web 300 either before or after activation via any suitablemeans. For example, in an embodiment, a pin punching unit, such as thepin punching unit described in, for example U.S. Pat. No. 6,849,319,which is incorporated herein by reference, may be positioned in betweenthe vacuum cylinder 106 and the IMG rollers 128, 130, or after the IMGrollers 128, 130, depending on the desired effect. Such additionalapertures may be arranged in a pattern having a mesh count of less than35 apertures per linear inch, for example. In an embodiment, a pinpunching unit may be used in lieu of the vacuum cylinder 106 and formingscreen 108 to form the plurality of apertured protuberances 312, after afilm layer has been laminated to the nonwoven web.

FIG. 4 is an enlarged photograph 400 of the side of the nonwoven layer320 that faces away from the formed film layer 310, i.e., the outsideface of the nonwoven layer 320. As illustrated in FIGS. 3 and 4, thenonwoven layer 320 includes a plurality of fibers 322 and a plurality ofpress-melted sites 324 that locally bond fibers together to form a webwith a generally uniform thickness and integrity for the nonwoven layer320. The fibers 322 are made from polymer, which may be a polyolefin,such as polypropylene.

Press-melted sites 324 are typical for a spun bond nonwoven, such as theone of this embodiment. Without the press-melted sites 324, the fibers322 would separate and fall away from each other, thereby taking awayfrom the integrity of the nonwoven layer 320. The press-melted sites 324may or may not be in register with the fusion bonds 330, as required oras desired. As is apparent from the embodiment illustrated in FIG. 3,the press-melted sites 324 are generally not in register with the fusionbonds 330.

U.S. Pat. No. 5,916,661, which is incorporated by reference, teachesthat press-melted sites, such as the press-melted sites 324 illustratedin FIGS. 3 and 4, also thin and weaken the fibers in the area whichmelted together while under a pressure point. The press-melted sites maybe formed with a patterned calendar roller and a smooth anvil rollerwhich may be heated and the pressure between the two rollers may beadjusted to provide the desired temperature and pressure to concurrentlyweaken and melt-stabilize the nonwoven web at a plurality of theselocations. This not only provides for web integrity with thepre-existing press-melted sites of any spun bond nonwoven, but moresites can be provided such that when activated with a pair of rollerswith intermeshing gears the press-melted, weakened fibers break to formopenings in the nonwoven. In this way, an activated nonwoven web withseveral openings existing at the press-melted sites may be formed.

FIG. 5 is an enlarged photograph 500 showing the plan view of thecomposite web 300 with several narrow lanes 510 and several wide lanes520. The wide lanes 520 are substantially comprised of a majority ofsmaller apertured protuberances 312, and the narrow lanes 510 arecomprised of larger apertured protuberances 312. Generally, one or twoapertured protuberances 312 in the narrow lanes 510 are enlarged. Widelanes are typically three, and sometimes four, apertures 314 wide inthis embodiment of the 57 BSC pattern. While the majority of apertures314 in the wide lanes are unaffected by activation, a few randomapertures 314 may become slightly larger. The lane widths and theirspacing are primarily determined by the intermeshing gear spacing andgear width. This can be varied for affecting different lane widths fordifferent mesh counts.

For this embodiment, the gears were spaced apart on centers at 0.105inches, have a width of 0.043 inches, and a height of 0.260 inches. Theyare slightly tapered and have flat, squared tips. In this embodiment,the basis weight of the formed film layer before activation was about11.7 g/m² (gsm). Combined with the 10 gsm nonwoven web, the sum of theoriginal components of the formed film layer 310 and the nonwoven layer320 before activation was about 21.7 gsm. However, the activated,lightweight, composite web 132 is lighter, at about 17.2 gsm. Therefore,the activated, lightweight, composite web 132 is lighter by about 20%than the sum of its original components. In the range of applicablebasis weights for the formed film layer 310 and for the nonwoven layer320, it is believed that most activated composite webs will be at leastabout 15% lighter to no more than about 25% lighter than the sum oftheir original components.

Most commonly, as with this embodiment, the narrow lanes 510 are alignedin the machine direction. In random spots, the narrow lanes 510 may havea wavy line for small segments along their length in the lightweightcomposite web 300. This does not harm their performance and may even addto the aesthetic value. Also, if desired, activation methods known inthe art may be used to create a lightweight composite web 300 where thenarrow lanes 510 are aligned in the cross direction.

Referring now to FIG. 6, a greater magnification photograph 600 of thelightweight composite web 300 is shown, focusing at just a few apertures616 from a narrow lane 510 and a few apertures 614 from a wide lane 520.

FIG. 7 schematically illustrates a more uniform graphic that illustratesthe differences between the apertures 614 in the wide lanes 520 and theapertures 616 in the narrow lanes. As illustrated, one narrow lane 510is between two wide lanes 520. Within wide lanes 520 are smallerapertures 614 with a major axis 610 and a minor axis 620. In thisgraphic, the major axis 610 of the smaller apertures 614 is aligned in afirst direction, vertically, along the machine direction (MD) axis 622.Within narrow lane 510 there are enlarged apertures 616 with a minoraxis 650 and a major axis 660. In this graphic, the major axis 660 isreversed in orientation and is aligned in a second direction,horizontally, along the transverse direction (TD) axis 624.

As illustrated in FIG. 7, for this 57 BSC embodiment, each of the widelane apertures 614 has a major axis 610 and a minor axis 620. Even ifpatterns of hexagons or circles were used, instead of a BSC pattern,when a formed film or a formed film composite is produced the machinerypulls the web downstream through a series of driven rollers and/ordriven nipped rollers. To keep the web free from wrinkles it isnecessary to have a slight increase in the speed of each subsequentdriven roller system. This is called ‘draw’. This machine direction drawwill impart into the pattern of the aperture 314 some extension to themachine direction axis 622 and some narrowing to the transversedirection axis 624. Thus, whether or not an intended BSC pattern isutilized, the result will be wide lanes 520 where the smaller aperture614 has a major axis 610 along the machine direction axis 622 and aminor axis 620 along the transverse direction axis 624. For thisembodiment, the smaller aperture 614 in wide lane 520 has the major axis610 aligned in the machine direction with a measurement of about 0.0080inches and the minor axis 620 aligned in the transverse direction with ameasurement of about 0.0045 inches.

Surprisingly, the apertures 616 in the narrow lanes 510 not only becomeenlarged but many of the enlarged apertures 616 have a reversed axisalignment. In this embodiment for example, the narrow lane's enlargedaperture 616 has a reversed axis orientation with the minor axis 650aligned in the machine direction and the major axis 660 aligned in thetransverse direction. The minor axis 650 of the enlarged apertures 616of this embodiment, aligned in the machine direction, measures about0.0075 inches. The major axis 660 of the enlarged apertures 616 of thisembodiment, aligned in the cross direction, measures about 0.0100inches. Thus, activation causes the effect where many of the narrow laneenlarged apertures 616 have a reversed axis compared to the smallerapertures 614 in the wide lane 520, with their major axis 610 in thetransverse direction and their minor axis 620 in the machine direction.

The area of the apertures 314, 614, 616 is calculated as the area of anoval: ½ the major axis 610, 660 times ½ the minor axis 620, 650 times3.14159 (Pi, π). For the wide lane's smaller aperture 614 of thisembodiment of FIG. 5, that yields the equation:0.004×0.00225×3.14159=0.0000283 square inches. For the narrow laneenlarged aperture 616 of this embodiment of FIG. 5, it yields theequation: 0.0050×0.00375×3.14159=0.0000589 square inches. Therefore, theenlargement factor of the enlarged apertures 616 compared to the smallerapertures 614 is about 200%. For the range of patterns useful for thisweb, activation may cause an enlargement factor of at least about 150%.

Referring now to FIG. 8, a magnified photograph 800 of the cross-sectionof the activated lightweight composite web 132 of the present inventionis shown. Photograph 800 shows a single narrow lane 510 separating twowide lanes 520. Wide lanes 520 exist in a first plane 810 and narrowlanes 510 exists in a second plane 820, different from the first plane810. The distance between the first plane 810 and the second plane 820is varied and will generally depend on the depth of engagement of theintermeshing gears 228, 230 of the activation step and how a specificpattern of protuberances and polymer blend in the formed film layerresponds to the activation stress. It will also depend, lane to lane, onthe slight variations of thickness and homogeneity throughout a web witha common nonwoven and formed film pattern and polymer blend.

Another theoretical advantage of these lanes 510, 520 in differentplanes 810, 820 may be that it provides extra coolness and comfort. In adiaper, for example, as the baby urinates and the warm urine accumulatesin the diaper core, warm, humid moisture vapors can develop. If thesevapors cannot escape fairly quickly, the diaper may become clammy anduncomfortable. Having narrow lanes 510 in the second plane 820 mayprovide a lateral or longitudinal void space as a pathway for moisturevapor escape. This concept is described in U.S. Patent ApplicationPublication No. 2003/0195487, which is incorporated herein by reference,and provides some data for an enhanced cooling rate if a void space isprovided. Thus, it is believed that the activated, lightweight,composite web 132 of the present invention has a feature that providessome void space for an enhanced cooling rate.

Referring now to FIG. 9 a selected area, which represents the multitudesof similar areas, is shown in a highly-magnified photograph 900.Photograph 900 shows a zone 910 with soft broken fiber ends 912reoriented to nearly vertical. It is well known in the art of tactilesensation that thin, vertical fiber ends, such as those experienced inbrushed cotton, for example, create a feeling of softness. U.S. Pat. No.7,351,297, which is incorporated by reference, teaches an activationwith a depth of engagement of the intermeshing gears that breaks apartsome of the nonwoven's fibers, forming fiber ends which create a higherdegree of softness. In this way, an activated nonwoven web with softbroken fiber ends reoriented to nearly vertical is concurrently formed.In the embodiment discussed herein, the nonwoven is a spun bondpolypropylene web, or “SBPP” and has a basis weight, in grams per squaremeter, or gsm, of an average of 10 gsm.

The activated, lightweight, composite web 132 described above is notonly lighter and softer than conventional webs of this type but it alsohas faster strikethrough time for synthetic urine. Strikethrough timetesting is conducted using a Strikethrough Apparatus according to EDANAERT 150.5-02 (including a funnel with magnetic valve, ring stand tosupport the funnel, strikethrough plate with electrodes, base plate, andelectronic timer) sold under the name Lister by Lenzing Technik ofAustria. The synthetic urine is a Saline Solution consisting of a 9 g/Isolution of analytical grade sodium chloride in deionized waterresulting in a surface tension of 70 mN/m (+/−2 mN/m) at 23° C. (+/−2°C.).

The web sample is cut to about 4 inches×4 inches and placed over a stackof absorbent papers. This stack is the placed under the Listerstrikethrough plate and the plate's orifice is aligned with funnel'soutlet. A sample of 10 ml of saline is introduced into the Lister plateorifice. When the saline is first present it touches electrical contactsin the orifice which creates an electrical circuit that starts a timer.Once the saline has struck through the web sample to be completelyabsorbed by the stack of papers, and thus has fully evacuated theplate's orifice, the circuit is broken which turns off the timer. Inthis way “Strikethrough Time” is determined and recorded. Ifstrikethrough time is slower than a functional time, urine mayaccumulate on the surface and move laterally, leaking out of the diaper.

Many combinations of nonwovens and formed films have existed in theabsorptive device market. Various uses are found such as acquisitionlayers and occasionally backsheets. They have not been generally used astopsheets, however, because they are heavy, lack softness, lack coolnessand many have slower strikethrough times. It is desirable for the formedfilm of the composite web to have apertured protuberances with a meshcount of greater than 35 to yield an activated composite web that islightweight and soft. In this embodiment, the mesh count was a 57 meshand the composite web was vacuum form laminated at 11.7 gsm, which is ajust under a half mil, which is considered to be very thin for a film.The apertures 314, 614, 616 are very small and not necessarily amenablefor functional strikethrough time.

When un-activated webs, or webs of less than about 0.16 inches ofactivation depth, were tested for strikethrough time, they had highvalues that averaged around 2.85 seconds. With activation depths of0.165 to about 0.180 inches, the strikethrough time dropped to 2.27seconds, about 25% faster. Within the range of webs of the presentinvention, it is expected that they will have strikethrough times ofless than or equal to about 2.5 seconds.

Absorptive devices where a layer of this web would be found highlyfunctional, especially as a topsheet or as an enhancement layer belowthe topsheet, include but are not limited to, baby diapers, adultincontinence devices, feminine napkins including the inter-labialoptions, tampons, panty liners, mops, cleaning cloths, absorbent padssuch as bed pads and spill pads, and the like. The web of the presentinvention is lightweight, soft and pliable and should perform well inany of these uses.

The embodiments described herein represent a number of possibleimplementations and examples and are not intended to necessarily limitthe present disclosure to any specific embodiments. Instead, variousmodifications can be made to these embodiments, and differentcombinations of various embodiments described herein may be used as partof the invention, even if not expressly described, as would beunderstood by one of ordinary skill in the art. Any such modificationsare intended to be included within the spirit and scope of the presentdisclosure and protected by the following claims.

What is claimed is:
 1. A method of manufacturing an activated compositeweb, comprising: laminating a film layer to a nonwoven web to form acomposite web; forming a plurality of apertured protuberances in thefilm layer with a pin punching unit; and passing the composite webthrough intermeshing elements to form an activated composite web, theintermeshing elements being constructed and arranged to form a pluralityof first lanes substantially unaffected by activation aligned in a firstdirection and having a first width in a second direction substantiallyperpendicular to the first direction, and a plurality of second lanesaligned in the first direction and having a second width less than thefirst width in the second direction in the activated composite web,wherein a first portion of the plurality of apertured protuberancesforms a plurality of first apertured protuberances having a plurality ofcorresponding first apertures with first cross-sectional areas, thefirst apertured protuberances being located in the first lanes, and asecond portion of the plurality of apertured protuberances forms aplurality of second apertured protuberances having a plurality ofcorresponding second apertures with second cross-sectional areas, eachof the second cross-sectional areas being larger than each of the firstcross-sectional areas, the second apertured protuberances being locatedin the second lanes, and wherein each of the first apertures has a firstmajor axis substantially aligned in the first direction, and each of thesecond apertures has a second major axis substantially aligned in thesecond direction.
 2. The method according to claim 1, wherein the filmlayer has a basis weight of between about 6 gsm and about 20 gsm.
 3. Themethod according to claim 1, wherein the nonwoven web has a basis weightof between about 8 gsm and about 18 gsm.
 4. The method according toclaim 1, wherein the plurality of apertured protuberances are arrangedin a pattern having a mesh count of at least
 35. 5. An activatedcomposite web, comprising a composite web having: a nonwoven layer; anda film layer attached to the nonwoven layer, the film layer comprising aplurality of apertured protuberances, wherein the composite web isactivated by stretching with intermeshing elements to form the activatedcomposite web comprising: a plurality of first lanes substantiallyunaffected by activation aligned in a first direction and having a firstwidth in a second direction substantially perpendicular to the firstdirection, wherein a first portion of the plurality of aperturedprotuberances forms a plurality of first apertured protuberances havinga plurality of corresponding first apertures with first cross-sectionalareas, the first apertured protuberances located in the first lanes; anda plurality of second lanes aligned in the first direction and having asecond width less than the first width in the second direction, thefirst lanes and the second lanes alternating with each other in thesecond direction, wherein a second portion of the plurality of aperturedprotuberances forms a plurality of second apertured protuberances havinga plurality of corresponding second apertures with secondcross-sectional areas, each of the second cross-sectional areas beinglarger than each of the first cross-sectional areas, the secondapertured protuberances located in the second lanes, wherein each of thefirst apertures has a first major axis substantially aligned in thefirst direction, and each of the second apertures has a second majoraxis substantially aligned in the second direction.
 6. The activatedcomposite web according to claim 5, wherein the film layer has a basisweight of between about 6 gsm and about 20 gsm.
 7. The activatedcomposite web according to claim 5, wherein the nonwoven web has a basisweight of between about 8 gsm and about 18 gsm.
 8. The activatedcomposite web according to claim 5, wherein the plurality of aperturedprotuberances are arranged in a pattern having a mesh count of at least35.